Improvement in valves for steam-engines



UNITED STATES PATENT OEEIoE.

LEONARD ATWOOD, OF NORWICH, CONNECTICUT.

IMPROVEMENT lN VALVES FOR STEAM-ENGINES.

' Specification forming part of Letters Patent No. 83,903, datedNovember 10, 1868.

To all whom it may concern Be it known that I, LEONARD ATWOOD, ofNorwich, in the county of New London and State of Connecticut, haveinvented a new and useful Improvement in Steam-Engines; and I do herebydeclare that the following is a full and exact description thereof,reference being had to the accompanying drawings, and to the letters ofreference marked thereon.

My invention relates to a new mode of constructing and operating asteam-counterbalanced slide-valve, and to novel means for reversing theaction of the engine by changing the course of the steam between thesteam chest and the cylinder, without changing the operation of thevalve.

In the accompanying drawings, Figure 1 is a longitudinal verticalsection through the center of the cylinder, steam-chest, and valve. Fig.2 is a view of the tumblers (hereinafter described) detached from theirseats,with the levers for operating them. Fig. 3 is a view of the underside of the base of the steam-chest, which fits onto the upper surfaceof the cylinder, showing the passage-ways for the steam to and from thecylinder. Fig.4is a detached view of the levers for operating thetumblers.

A is the cylinder; B, the steam-chest, and B the base of the steamchest,in which are located the tumblers C and C, as well as the ports orsteam'passages from the steam-chest to the cylinder and from thecylinder to the exhaust-pipe. Vis the steam-counterbalanced valve. D isa partition-plate, screwed down upon a flange, c, in the steam-chest,dividing the same into two compartments, with an opening, d, throughwhich the exhaust-steam escapes; and 0 o are two ports or steam-passagesleadingfrom the steam-chest to the tumblers C and C. E is theexhaust-pipe. C and C are two hollow cylindrical tumblers orintermediate valves between the steam-chest and the cylinder. From thesocketseats of said tumblers to the cylinder there are four passage-waysfor the steam to and from the cylinderviz.,e e and ff. In the upper sideof each of said cylindrical tumblers there is a slot oropening,ii',through which the steam from the steamchest enters theinteriors of said tumblers; and there are other slots or openings insaid tumblers-viz., g and g in C and h in Cby means of which the steampasses to and from the cylinder through the ports 6 e and ff, accordingto the position in which said tumblers are turned.

F and F are two levers for operating the tumblers, and F is a linkconnecting them together, so that they may be operated simultaneously bymeans of the handle C.

When these tumblers are turned from right to left, as in Fig. l, theslot 9 in the tumbler C will come opposite the port 6, and admit steamto the end A of the cylinder, while at the same time the slot h intumbler C will come opposite the port-f, and allow the exhauststeam toescape from the opposite end. A of the cylinder; but when the levers areturned so as to incline in the opposite direction, the slot g in tumblerC will come opposite the port 6, and admit steam to the end A of thecylinder, while at the same time the slot h in tumbler C will comeopposite the port f, and allow the exhaust-steam to escape from the endA of the cylinder, thus reversing the motion of the engine without anychange in the movement of the valve.

When the handle G is vertical all the ports leading from the tumblers tothe cylinder are closed, and the steam completely shut off from thecylinder.

The tumblers C and C should be made slightly tapering from their frontto their rear ends, and their socket-seats of corresponding form. Theyshould be drawn tightly into their socket-seats by means of screws andnuts on their rear ends at Z 1. Any loosening from wear can thus bereadily obviated.

It will be obvious that, by means of this simple device for reversingthe action of the engine, the necessity for any more than one eccentricfor operating the valve is completely obviated, and much heavy andexpensive machinery heretofore used is dispensed with.

On the under side of the valve V, between its two ports, the metal iscut away, as shown at n, Fig. 1, so that the steam in the steamchestwill act upon the under side of said valve, to counterbalance thedownward pressure upon its upper surface and lessen the friction.

Having thus fully described my invention and its mode of operation, whatI claim as 3. The steam-counterbalanced valve V, connew, and desire tosecure by'Letters Patent, is structed as described, when arranged and0p- 1. ll'itermediate valves between the steamcrating in relation tothep'late D, substanchcst and cylinder, to reverse the action of thetially as described.

engine by changing the course of the steam after it has passed the mainor induction and LEONARD ATWOOD. eduction valve, substantially asdescribed.

2. The tumblers G and O, in combination WVitnesses:

With the steam-passages e,e,f, and f, sub- J. J. COMES, stantially asand for the purpose described. JOHN'OQON.

